hi Greg,

Patch revised for 3.0.

Thanks,
NeilBrown


From 30de5989902b5613c7643a695ed32446ecd477de Mon Sep 17 00:00:00 2001
From: NeilBrown <[email protected]>
Date: Thu, 12 Apr 2012 16:05:06 +1000
Subject: [PATCH] md/bitmap: prevent bitmap_daemon_work running while
 initialising bitmap

commit afbaa90b80b1ec66e5137cc3824746bfdf559b18 upstream.

If a bitmap is added while the array is active, it is possible
for bitmap_daemon_work to run while the bitmap is being
initialised.
This is particularly a problem if bitmap_daemon_work sees
bitmap->filemap as non-NULL before it has been filled in properly.
So hold bitmap_info.mutex while filling in ->filemap
to prevent problems.

This patch is suitable for any -stable kernel, though it might not
apply cleanly before about 3.1.

Cc: [email protected]
Signed-off-by: NeilBrown <[email protected]>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 703a3fa..2eba9a1 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1897,7 +1897,9 @@ int bitmap_load(mddev_t *mddev)
                         * re-add of a missing device */
                        start = mddev->recovery_cp;
 
+               mutex_lock(&mddev->bitmap_info.mutex);
                err = bitmap_init_from_disk(bitmap, start);
+               mutex_unlock(&mddev->bitmap_info.mutex);
        }
        if (err)
                goto out;

Attachment: signature.asc
Description: PGP signature

Reply via email to